tion; lack of multiple measures of outcomes from multiple sources; and insufficient long-term follow-up, which can prevent the collection of outcome data on incidence of multiple disorders. Perhaps the best chance to deal effectively with these sorts of problems lies in the application of a comprehensive set of rigorous standards for preventive intervention research.

Treatment Intervention Research

Effective psychosocial and pharmacological treatments are now available for many mental disorders (Kaplan and Sadock, 1989; Karasu, 1989; Dobson and Shaw, 1988). When these treatment interventions are used, they can substantially reduce the morbidity, chronicity, and disability of mental disorders. One justification for mining the principles grounded in treatment intervention research for use in preventive intervention research programs is that preventive interventions and treatment interventions are often based on similar multifactorial causal models. Therefore it is possible that if a particular treatment intervention is effective for treating an already developed mental disorder, the same or similar intervention may be effective in preventing the disorder in individuals who are at high risk.

For example, many treatment studies have shown that when language, communication, and social skills are improved—giving individuals more functional control in their environments—disruptive, aggressive, self-injurious, and stigmatizing behaviors can be greatly reduced (Liberman, 1988). In addition, identification of prodromal phases for disorders such as depression, schizophrenia, and agoraphobia, combined with educational campaigns designed to promote early identification, could facilitate use of interventions, such as cognitive-behavioral approaches for the individual and his or her family, to push the boundaries from treatment into indicated preventive interventions for individuals at high risk for developing a disorder.

In addition to lessons on risk and protective factors and causal chains, Chapter 8 lists a number of other possible applications to prevention from treatment. All are presented with cautious optimism and the realization that only a growing body of empirical trials of preventive interventions can validate their applicability. For example, evidence from treatment research has shown that there is a high rate of co-morbidity in mental disorders. Half of persons with mental disorders have more than one diagnosis (Wolf, Schubert, Patterson, Grande, Brocco, and Pendleton, 1988). This evidence on co-morbidity suggests several rationales for preventive intervention research (Kessler and

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